Recording apparatus



March 1, 1955 1.. E. W006 2,703,269

RECORDING APPARATUS Filed Oct. 8, 1951 LCILLTVU E. Wcod.

ATTORNEY United s ates Patent RECORDING APPARATUS Louvan E. Wood, Glenarm, Md., assignor to Bendix Aviation Corporation, Baltimore, Md., a corporation of Delaware Application October 8, 1951, Serial No. 250,324

2 Claims. (Cl. 346-105) This invention relates to recording apparatus of the type in which a measured value of a variable magnitude is represented upon a record receiver. More particularly, the invention relates to the type of recorder by which a symbol or indicia is transferred to a moving record chart to provide a permanent record as well as an instantaneous indication of the measured magnitude.

One form of recording apparatus of the type above referred to is the helix-drum type which includes a cylindrical member having disposed upon its surface a helical rib. This member is driven rotatably either at a constant speed or as a function of a variable magnitude. Cooperating with the rotating drum and rib is the record receiver which may take the form of a paper chart and which is driven past the drum, usually at a constant speed, to provide a time reference. Overlying the chart is an inking ribbon or tape which is rolled in a direction transverse to the longitudinal axis of the moving chart, ordinarily from a supply roll on one side of the chart to a take-up roll on the opposite side. Spaced above the inking ribbon is a depressor bar or tapper bar having a length corresponding to the projected length of the helical rib upon the drum member. The depressor bar is driven in an oscillatory motion either as a function of the measured magnitude or as a function of time and in the lowermost position of its oscillatory path it co-acts with the spiral rib to clamp the ribbon and chart therebetween and thus produce an index mark at the point of intersection of the bar and rib.

In the prior existing recorders of this type the inking ribbon generally has a considerable width relative to the size ofthe imprinted index mark and thus the index mark is obscured to vision until the travel of the chart is sufficient to remove the index mark from under the inking ribbon. In many applications it is highly desirable to employ the recorder device not only for the purpose of making a permanent record of the measured values over a period of time but also to employ the device as an indicator; that is, an indicator in the sense that the value of the measured condition may be observed substantially at the same instant it is translated to the record receiver.

In prior forms of the apparatus the depressor bar in its travel toward the chart engages the ribbon and translates the engaged length in a substantially planar section. This has resulted in a somewhat indistinct or smeared index point upon the chart rather than a sharp and distinct image. Furthermore, when the ribbon is translated in its position by the depressor bar, particularly in apparatus where the depressor bar has a relatively high velocity, air resistance is encountered which may have an appreciable effect upon the sensitive response of the instrument.

Accordingly, it is an object of the present invention to present an improved form of the recording apparatus discussed above which substantially eliminates all of the undesirable characteristics enumerated.

A particular object of the present invention is to provide a recorder having a printing member and inking tape which permits observation of the printed symbols substantially simultaneously with the printing operation.

Another object is to present a recorder which will produce clear and distinct index marks or images.

Another object is to reduce the resistance encountered in the translation of the inking ribbon into contact with the record receiver.

These objects and others and the method of accom- Patented Mar. 1, 1955 plishment and the novel features of the present invention will become apparent upon a consideration of the following description, together with the accompanying figures. It is to be expressly understood that the figures are to be construed as merely illustrative and not as a definition of the limits of the present invention.

Figure l is a perspective view of the printing apparatus of a recorder embodying the novel features of the present invention.

Figure 2 is a sectional view taken through the axis of rotation of the platen member showing one configura tion of the inking tape contemplated by the present invention.

In recording apparatus of the type to which this invention is applicable the inking tape may be of the type conventionally used for typewriters and usually is wound upon a spool or reel in a substantially flat condition. The tape in existing recorders is passed between the printing member and the chart in this flat condition. It has been discovered that if the tape lying between the printing member and record receiver is conditioned so that the portion between the observer and the printing member is up-turned forming the ribbon into two plane sections intersecting at an angle less than degrees, numerous advantages may be realized. In order to permit observation of the recorded symbol substantially at the same time it is imprinted upon the record receiver, the angular displacement with respect to the plane of the record receiver of the plane section of the tape between the observer and printer must be somewhat in excess of the angular displacement of the observers line of sight with respect to the plane of the record receiver. The manner in which this may be achieved and the advantages secured therefrom will appear hereinafter.

Referring to Figure 1 there is shown at l a cylindrical drum having disposed upon its surface a helical rib 2,

comprising a driven platen. Disposed in a horizontal plane above the platen member is a record receiver or chart 3 which is driven continuously by suitable drive means. Overlying the record receiver is shown a printing member or tapper bar 4 which is given an oscillatory motion by a suitable power transmission means and which in the lowermost position of its travel engages an image transfer member or inking tape 5. As is well understood by those skilled in the art, the inking tape and chart are pressed. into' engagement by the tapper bar with the helical rib of the platen member to produce an index mark upon the chart at the point of intersection of the rib and bar.

In order to continually supply a fresh portion of inking tape to the printing device the tape is furnished from a supply roll 6 from which it is passed over a roller 7 which may be employed to change the direction of travel of the tape and to insure that the tape passes to or from the roll in a flat condition. From the roller 7 the tape is passed through a tape conditioning assembly comprising guide members 8 and 9, thence over the record receiver to a second tape conditioning assembly comprising guide members 10 and 11 and over roller 12 t0 the tape take-up roll 13. The take-up roll is mounted for rotation upon a power driven shaft 14 supplied by appropriate drive means. The drive means and power transmission means referred to form no part of the present invention and are of the conventional type employed in recorders. Illustration and description are omitted for the sake of brevity.

In the embodiment illustrated the conditioning means for the tape is shown at 8 and 9 as a two-part guide. The part 9 comprises a shaft-mounted disc having its periphery tapered from both faces to provide a tongue member of V-shaped cross section. The second part 8 as shown is another shaft-mounted disc having its periphery tapered from either face to provide a groove having a V-shape in cross section to complement the tongue on the periphery of member 9. Th tongue and groove peripheral edges of the complementary parts are inter-engaged and have a clearance sufficient to permit the tape member to be fed therethrough.

It will be apparent that tape fed from the supply roll in its flat condition through the tape conditioning member just described will emerge with a cross sectional configuration conforming to the clearance space between the meshed tongue and groove members. Thus the tape is supplied across the record receiver in this form having its Width divided into two plane sections 15 and 16, the planes intersecting on a line or crease, 17, defining a longitudinal axis of the tape. The second tape conditioning member, 10, 11, in all respects the same as that described above, is mounted on the opposite side of the record receiver and performs the same function as the first, the only difference being that the tape is fed through in a reverse direction. The second member is particularly desirable where the span of the ribbon across the record receiver is appreciable and the preformed ribbon tends to sag and distort in its shape under its own Weight. The configuration of the ribbon in its cross section is clearly shown in Figure 2.

In Figure 2 is shown the cross sectional view of the blade portion of the tapper bar. The lower portion of this blade is provided with a knife edge for cooperation with the ribbon at the lowermost point of the preformed trough.

It will now be apparent that observation of the printed index mark is facilitated by the arrangement described above. Observation of the index mark will be permitted substantially at the same time the mark is imprinted if the leading edge 15 of the tape is superelevated or inclined at an angle with respect to the record receiver which is greater than the angle of incidence of the line of sight of an observer. Having the rear portion of ribbon 16 superelevated or inclined upwardly from the recorder chart is desirable in order to produce an image or mark that is clear and distinct. With both surfaces of the ribbon inclined with respect to the chart the surface contact between the ribbon and chart is minimized. It will be recognized by those skilled in the art that still a further advantage is gained from the construction described in that the ribbon is given a streamlined effect in the direction of its travel and thus the frictional resistance to motion is decreased and the response sensitivity of the instrument is increased.

Although but one embodiment of the invention has been shown and described in detail, it is to be expressly understood that this embodiment is merely illustrative and in no sense defines the limits of the invention. Various modifications in the design and arrangement of parts will now occur to those skilled in the art without departing from the spirit and scope of the present invention.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a recorder of the type which includes a platen,

a record receiver adjacent said platen and moving in a first direction, a printing bar, and a transfer tape supplied adjacent said record receiver and extending transversely to said first direction for cooperation with said printing bar to produce a mark upon said record receiver, the combination with said tape of supply means therefor and means disposed at opposite ends of said platen for conditioning said tape for coaction with said printing bar and said record receiver, said last named means including a first member having a recessed surface forming a V-shaped groove and a second member having a tongue corresponding to said groove and spaced from said recessed surface to provide a clearance therebetween to accommodate and deform said tape in its lateral crosssection, whereby said mark is visible to an observer substantially instantaneously with the recording thereof.

2. In a recorder of the type specified, a platen, a record-receiving sheet adapted to be fed adjacent said platen in a first direction, a printing bar mounted for coaction with said sheet and platen, means for feeding a transfer tape or ribbon between said sheet and printing bar in a direction substantially transverse to the direction of feed of said sheet, and means located at opposite ends of said platen for conditioning said tape for coaction with said printing bar and said sheet, said conditioning means including coacting members disposed on opposite sides of the path of feed of the tape and defining a pass for the latter, one of said members having a substantially V-shaped recess and the other of said members having a projecting tong or raised portion corresponding in contour to said groove or recess, said conditioning members functioning to deform the moving tape in lateral cross section and thereby constantly maintain the tape on opposite sides of said printing bar clear of said sheet, the magnitude of deformation being at least sufiicient to render the printed indicia visible to an observer substantially instantaneously with the recording operation.

References Cited in the file of this patent UNITED STATES PATENTS 1,598,739 Mettler Sept. 7, 1926 2,205,450 Wise June 25, 1940 2,346,044 Nadeau Apr. 4, 1944 2,500,746 Ellenberger Mar. 14, 1950 2,521,881 Suomi Sept. 12, 1950 FOREIGN PATENTS 114,217 Sweden July 21, 1939 

